Fraction collector



y 1966 E. DURRUM ETAL 3,252,763

' FRACTION COLLECTOR Filed Aug. 4, 1961 2 Sheets-Sheet l /9-l k/a v EMMETT L lggjgggir FI 501M420 G. P/CKELS A TTOEA/EYS y 4, 1966 E. L. DURRUM ETAL 3,252,763

FRACTION COLLECTOR 2 Sheets-Sheet 2 Filed Aug. 4, 1961 FIE '2 IE IE IEI f1 l3 El E L WW J W NPK m mum 7 m w me D me 4 MW 5% United States Patent 3,252,763 FRACTION COLLECTOR Emmett l... Dun-um, Woodside, and Edward G. Pickcls, Atherton, Calif., assignors to Beckman Instruments, Inc, a corporation of California Filed Aug. 4, 1961, Ser. No. 129,447 3 Claims. (Cl. 23-253) This invention relates generally to a fraction collector and more particularly to a fraction collector employing a collecting medium.

In many biological and chemical analyses, successive fluid aliquotes, as from an analyzing apparatus, are collected and analyzed. These aliquotes have, in the past, been collected in automatic fraction collectors. In general, such fraction collectors comprise a mechanism for successively presenting collecting vessels, such as test tubes, to receive the sample being supplied from the separating apparatus. Another method of analysis is one in which the fluid is continuously analyzed as it leaves the analyzing apparatus to provide a continuous record of the fluid composition.

A typical apparatus of the above character might be an amino acid analyzing apparatus employing ion-exchange chromatography. The output stream includes the separated amino acids. This stream is treated and colorimetrically analyzed. In other chromatographic ion exchange apparatus, the output stream has aliquotes collected in test tube presented by a fraction collector. The

fluid aliquotes are substantially analyzed. In continuous flow separations, the fractions may becollected by a fraction collector.

In general, the prior art apparatus and methods for collecting the. sample require relatively large amounts of sample. Because of the large amounts of sample required, a long period of time is required to collect sufficient fractions for an analyzing operation. Consequently, the resolution is often incomplete.

It is a general object of the present invention to provide an improved fraction collector and method.

It is a further object of the present invention to provide a fraction collector in which the fraction can be concentrated.

It is a further object to provide a fraction collector having improved resolution.

It is another object of the present invention to provide a fraction collector and method capable of collecting relatively small samples on an absorbent collecting medium.

It is still another object of the present invention to provide a fraction collector and method in which the sample fractions collected on a collecting medium can be easily indexed, sample portions analyzed and other sample portions stored.

It is still another object of the present invention to provide a fraction collector and method in which the sample is collected by scanning an absorbent collecting medium. The collecting medium may then be cut up and scan portions stored, others eluted and analyzed and still others developed and subjected to colorimetric analysis.

It is another object of the present invention to provide a simple inexpensive fraction collector which is easy to operate.

These and other objects of the invention will be more clearly apparent from the following description when ice FIGURE 3 is a view taken along the line 3-3 of FIGURE 2; I

FIGURE 4 shows another method of scanning a fraction collecting medium;

FIGURE 5 schematically illustrates the use of the apparatus of the present invention in conjunction with conventional fraction collectors to index the fractions collected by the conventional sample collector;

FIGURE 6 illustrates the use of the collecting medium to provide indexing, storage and analysis;

FIGURE 7 shows a collecting medium having fractions applied thereto in discrete areas; and

FIGURE 8 is a schematic circuit diagram illustrating a suitable circuit for operating the device of FIGURES 2 and 3.

FIGURE 1 shows a portion of a fraction collecting medium 11 taken from an elongated tape-like medium. The collecting medium may be an absorbent material such as filter paper. It may however be non-absorbing. The collecting material collects and retains the fractions. There is shown a plurality of traction regions 12 applied to the collecting medium. The fraction regions, in general, will have an area corresponding to the rate-time which the fraction is applied at the predetermined point on the collecting medium. In order to further limit the area of the fraction regions, heat may be applied in the form of hot air or by a heated surface below the collecting medium. Thus, the fraction may be dried rapidly before it has time to spread over a large area of the collecting medium. In this manner, the concentration of 'the fraction may be increased. As illustrated, the areas are arranged in longitudinally spaced transverse scans.

The sample may be applied to the collecting medium by an applicator 13 carried by an arm 14. The applicator 13 is connected through a flexible tubing 16 to the separating apparatus whereby the fractions are conveyed from the separating apparatus to the applicator. A nozzle 15 connected to a supply of hot air or other gas is also connected to the arm 14 and is directed at the collecting medium below the applicator 13.

Referring to FIGURE 2, there is schematically illustrated a separating apparatus including an ion exchange resin column 17. As is well known, a buffer solution is pumped into the upper end of the column, as indicated by the .arrow 18. A sample solution to be separated into fractions is also applied to the upper end of the column, as indicated by the arrow 19. As the sample and buffer are pumped down through the column, the resin retards the different sample fractions for characteristic lengths of time. When the stream of fraction emerges from the bottom of the column, it is applied through the tubing 16 to the applicator 13.

The applicator applies the fraction to the tape-like collecting medium 11 which is drawn from the storage roll 18 by a suitable tape drive means. The drive means illustrated comprises an idler roller 21 and a driving roller 22 driven by the motor 22a which may be geared to provide the desired rotative speed. The filter paper is disposed between the rollers and rotation of the drive roller serves to unwind the paper from the roll 18 and move it in the direction of the arrow 23 past the applicator 13.

A guide roll 24 may 'be provided for guiding the paper as it travels over the back-up member 26. The back-up member extends across the apparatus and is provided with a trough or groove 27 opposite the applicator 13. If it is desired to limit the size of traction area on the collecting medium, the groove 27 may include a heating means such as an electrically heated plate 25 rather than the hot air nozzle 15 shown in FIGURE 1. The backup member 26 is provided at its ends with spaced rollers 28 which ride in the grooves 29 formed in the spaced guides 31 carried on the sides 43 of the apparatus. The back-up member can be moved up and down to selectively bring the collecting medium in contact with the applicator 13.

A driven cam roller 32 engages the bottom of the back-up member 26. The cam roller 32 is driven by a drive motor 30 which may be geared to provide the desired rotative speed. The cam roller 32 is provided with a projecting cam portion 33. Suitable means are provided for urging the back-up member downwardly against the cam. For example, spaced springs 34 may be provided for drawing the back-up member downwardly against the roller 32. Rotation of the cam roller will serve to intermittently cam the back-up member upwardly as the projecting portion 33 engages the bottom surface. Thus, the collecting medium is periodically moved into contact with the applicator 13.

As an alternative means for providing periodic contact between the applicator and the collecting medium, the arm 14 may be periodically lifted by means such as the cam 35 (FIGURE 1) which extends across the path of the arm.

Spaced in the direction of travel of the tape-like absorbent medium is provided means for drying the paper. For

- example, such means might comprise a radiant heating lamp 36 for radiating the bottom surface of the filter paper.

Suitable means are provided for causing the applicator 13 to scan transversely the tape-like collecting medium. For example, the applicator 13 may be mounted on the end of a flexible arm 14 which is secured to the block 41 carried on the top place 42, which in turn, is secured to the upper edge of the sides 43. Spaced along the arm there is provided a cam roller 51 which is adapted to engage a driven cam plate 52. The cam may, for example, be driven by a geared motor 53 mounted on the top plate 54 carried by the sides 43. Rotation of the cam plate serves to cause the cam roller 51 to follow and the flexible arm 14 to flex and attain positions intermediate those shown in solid and dotted line in FIGURE 3.

Limit switches 56 and 57 may be provided on opposite sides of the apparatus. They are positioned whereby they are operated by the arm 14 as it reaches its two extremes of travel. The switches 56 and 57 may be connected in a circuit of the type shown in FIGURE 8. The switches are connected in parallel to the winding 61 of an electromagnetically driven rotary switch 62. Thus, as the switches 56 and 57 are operated by the arm, the contact member 63 is advanced through one step. Alternate contacts are connected in common to a first line 64, while the common line 60 provides the other output terminal. The lines 64 and 60 are connected to drive the motor 30. The cam roller 32 is rotated only when applicator 13 is scanning counter-clockwise as viewed in FIGURE 3. By suitably selecting the speed of the motor 30, as many application areas 12 as desired may be provided for each scan across the apparatus. Alternatively, by suitable selection of a cam, the motor 39 may be adapted to drive and hold the back-up member 26 in such a position that the scan is in the form of continuous longitudinally spaced lines of the type shown at 66 in FIGURE 4. The number of areas may be controlled by appropriately designing the cam and adjusting the speed of the motor 30. Thus, less fraction areas may be formed than those shown in FIGURE 1; see FIG- URE 7.

It is apparent that the collecting medium can be cut up into pieces, each including a fraction area. The fractions on the pieces can then be analyzed chemically or photometrically. This is illustrated in FIGURE 6 wherein the strip is cut into three longitudinal portions. The first portion 71 might, for example, be treated and subjected to a colorimetric analysis to identify the sample fractions or components. Selected portions of the longitu-dinal strip 72 may be cut out, eluted and chemically analyzed. The portion 73 may be indexed and stored for future analysis or comparison. Clearly, the same procedure can be carried out with the area scans shown in FIGURES 1 and 7.

In certain analyses, it may be desirable to continuously analyze fractions and still provide a continuous record on a collecting medium 11. Referring to FIGURE 5, the column 17 is shown supplying a major portion of the sample fractions to a test tube 81 carried by a conventional fraction collector 82. A small amount of the fluid can be bypassed and applied to applicator 13 to provide a record 12 on a collecting medium 11.

Thus, it is seen that there is provided a sample collector which can be used to provide permanent storage of sample fractions and rapid colorimetric chemical analyses of sample fractions. The fraction collector is simple in construction, efiicient in operation and requires only relatively small quantities of sample fractions.

We claim:

1. A fraction collector comprising a tape forming a fraction collecting medium, said tape having a surface for receiving fractions;

an applicator for applying said fractions to said tape surface;

means for causing relative longitudinal motion between said applicator and said tape;

means for causing relative lateral motion between said applicator and said tape surface; and,

means for periodically bringing said tape surface and said applicator into contact whereby fractions are applied to longitudinally and laterally spaced portions of said surface.

2. A fraction collector, as defined in claim 1, which includes a fixed base; and in which said means for causing relative lateral motion between said applicator and said tape surface comprises a resilient arm attached at one end to said fixed base and mounting said applicator at the other end; and,

a cam mechanism for deflecting said resilient arm whereby said end mounting said applicator moves laterally over said tape surface.

3. A fraction collector, as defined in claim 1, which includes means for drying said fractions contemporaneously with said application of said fractions to said tape surface.

References Cited by the Examiner UNITED STATES PATENTS 1,941,962 1/1934 Tone 11725 2,029,922 2/1936 Heckel et al. 154-2 2,037,822 4/1936 Robert 117--25 2,113,063 4/1938 Stryker et al. 23-255 2,129,754 9/1938 Yagoda 23-253 2,654,522 10/ 1953 Gorham.

2,751,310 6/1956 Kline et al. 11737 2,937,107 5/1960 Phillips 117l19.8 X 2,962,383 10/1960 Francl et al. ll737 3,011,213 12/1961 Brandon et al. l18323 X 3,098,719 7/1963 Sk'eggs 23253 OTHER REFERENCES Glick, D.: Methods of Biochemical Analysis, vol. I, Interscience Publishers, Inc., New York (1954), pages 196 and 250.

WILLIAM D. MARTIN, Primary Examiner.

RICHARD D. NEVIUS, Examiner.

V. E. SULLIVAN, H. W. MYLIUS, Assistant Examiners. 

1. A FRACTION COLLECTOR COMPRISING A TAPE FORMING A FRACTION COLLECTING MEDIUM, SAID TAPE HAVING A SURFACE FOR RECEIVING FRACTIONS; AN APPLICATOR FOR APPLYING SAID FRACTIONS TO SAID TAPE SURFACE; MEANS FOR CAUSING RELATIVE LONGITUDINAL MOTION BETWEEN SAID APPLICATOR AND SAID TAPE; MEANS FOR CAUSING RELATIVE LATRAL MOTION BETWEEN SAID APPLICATOR AND SAID TAPE SURFACE; AND, MEANS FOR PERIODICALLY BRINGING SAID TAPE SURFACE AND AND APPLICATOR INTO CONTACT WHEREBY FRACTIONS ARE APPLIED TO LONGITUDIANLLY AND LATERALLY SPACED PORTIONS OF SAID SURFACE. 